- Greek vases were made of terra cotta or baked clay.
Before the clay could be used for pottery,
pebbles and other impurities had to be removed.
First, the potter mixed the raw clay with water
in large outdoor pools to make a thick, silty liquid.
This liquid clay stood until the
heavier impurities had settled to the bottom.
The refined liquid was then drained off into a second pool.
The potter repeated this settling process several times.
The pool was then left to evaporate in the sun,
leaving behind the refined clay.
The final step in preparing the clay for potting
was called "wedging".
The potter systematically compressed and folded the clay,
making it more malleable and mixing together
any parts that may settled into layers.
The clay was now ready for use.
Most Greek vases were thrown
or formed on the potter's wheel.
The complex shapes of Greek pottery often required
that a vase be thrown in pieces and then assembled.
For example, to make a kylix or cup
the potter first centered the clay on the wheel.
When it stopped wobbling the potter began a central hole.
Pressure from the potter's fingers inside the hole gradually
widened this opening and formed the bowl of the cup.
Aside from the wheel, the potter's main tools
were his hands.
Although a wet sponge was often used to smooth the surface.
To make the foot of the cup,
the potter again centered the clay, drew it up,
and then hollowed out the stem.
The next day when the formed pieces had dried slightly,
the bowl of the cup was trimmed with a metal shaver
and received a final smoothing.
The potter used wet clay to bond
the separately made bowl and foot,
and then smoothed over the join.
Next, the potter stretched out lengths of clay
and bent them into handles.
Again using wet clay the potter
attached the handles to the bowl.
Often roughening the joining surfaces to increase the bond.
The vase was now ready to be decorated.
Athenian vase painters experimented with
a number of different methods of vase decoration.
To create a vase in the black figure technique,
that is, with black figures against a red background.
The vase painter first sketched the outline of the design,
in this case a dolphin,
onto the surface of the vessel.
Then, using a highly refined liquid clay as paint
the vase painter filled in the outline,
creating a silhouette.
When applied, the clay paint was almost the same color
as the surface of the vase.
But with firing it would turn black.
The vase painter next used a sharp point to
scratch internal details through the silhouette.
The vase was then ready for the kiln.
The contrasting red and black
color scheme of Athenian pottery
was the result of a difficult three stage firing process.
Using wood-fired kilns or ovens,
vases were heated to about 800 degrees centigrade
in an oxygen-rich environment,
causing the whole vase to turn red.
Next, the potter closed off the vents of the kiln
and added green wood and leafy branches
creating an oxygen poor environment.
As a result, the whole vase turned black.
At the same time, the kiln temperature was raised
causing the thin painted layer of decorative clay
to become glossy and nonporous.
Finally the kiln was allowed to slowly cool,
and the potter reopened the vents
letting oxygen into the kiln again.
In this stage the unpainted areas of the vessels
returned to their warm red color.
But the glossy areas, which could not absorb oxygen,
remained black.